When National Grid unveiled its proposal for the Moorside project last October, it said it planned to put lines underground and under Morecambe Bay to protect the Lake District National Park and that more than a quarter of the connection could be underground. According to the proposal, some 23.4km (14.5 miles) of new line is to be laid underground through the entire western section of the national park. This could see the existing lines there being removed completely, leaving this part of the park free of pylons for the first time in 50 years, the National Grid said. This would be in addition to: putting cables through a tunnel measuring about 22km under Morecambe Bay to avoid the south part of the national park at a cost of £1.2 billion; removing many of the existing pylons owned by Electricity North West (ENW) and replacing them with fewer, taller pylons of its own operating at a greater voltage; and replacing the low voltage line in the area around the Hadrian's Wall UNESCO World Heritage Site with underground cables.

National Grid said it was confident that along the 164km route of the proposed connection, it could remove many of the existing pylons owned by ENW, which carry low voltage power lines around the west coast of Cumbria. It would replace them with fewer, taller pylons carrying lines of its own operating at a higher voltage. Engineers are already developing proposals, it said when it announced the proposal, for a £1.2 billion tunnel under Morecambe Bay, which would avoid putting new lines through the southern part of the Lake District.

National Grid had aimed to submit an application for consent to build the new connection to the Planning Inspectorate this year. A decision would then be made by the Secretary of State for the Department of Business, Energy and Industrial Strategy. If consent were granted, construction work would be expected to start in 2019. National Grid also said it was contracted to provide NuGen with the first phase of the connection into its transmission network by 2024.

Transmission is apparently a substantial challenge from the Sellafield (Moorside) site to the load centers in the rest of the country.

Toshiba Corp is considering liquidating its British nuclear unit NuGen, two people with direct knowledge of the matter said on Thursday, leaving Britain to seek alternatives for a project that was meant to provide 7 percent of the country’s electricity. The move comes as Toshiba believes talks to sell the unit have dragged on too long, the sources told Reuters. “Toshiba is eager to shut off potential risks associated with NuGen soon,” one of them said. Both sources declined to be identified as the talks are private. Britain needs to invest in new capacity to replace aging coal and nuclear reactors that are due to close in the 2020s, but large new plants, especially nuclear have struggled to get off the ground due to high costs and weak electricity prices. The NuGen project in Moorside, northwest England, faced setbacks after Toshiba’s nuclear arm Westinghouse went bankrupt last year.

Toshiba plans to wind up its UK nuclear business after failing to find a buyer, dealing a potentially fatal blow to plans for a new nuclear power station in Cumbria. Its NuGen division was behind the development of the Moorside project. Toshiba's decision will dent the UK's plans to develop new nuclear power stations. Unions have criticised the government for failing to intervene and ensure the project went ahead. The Japanese firm said it would start the wind-up process in January. "After considering the additional costs entailed in continuing to operate NuGen, Toshiba recognises that the economically rational decision is to withdraw from the UK nuclear power plant construction project, and has resolved to take steps to wind-up NuGen," the Toshiba statement said.

Toshiba Corp. TOSYY 9.56% said Thursday it would liquidate its U.K. nuclear business and sell its U.S. natural-gas business, taking a combined loss of nearly $1 billion. The moves are intended to clear away legacy problems after Toshiba went through waves of restructuring in the past three years that included the bankruptcy of its former Westinghouse Electric business in the U.S. The U.K. business—NuGeneration Ltd., known as NuGen—had sought to build what was planned as Europe’s largest new nuclear project in northwest England. The Moorside project stumbled amid doubts about the economics of nuclear-power plants.

Westinghouse's bankruptcy continues to devastate their former parent Toshiba.

Toshiba acquired 60% of the outstanding shares of NuGen, a UK-based new nuclear development company that planned to construct a nuclear power plant on the West Cumbria coast in northwest England, in June 2014. Toshiba subsequently acquired the remaining 40% of NuGen’s shares from France’s ENGIE S.A. (hereinafter “ENGIE”) in July 2017, when ENGIE exercised its right to sell its entire shareholding to Toshiba. This was the result of the filing of a voluntary petition under Chapter 11 of the U.S. Bankruptcy Code by Westinghouse Electric Company and others, which triggered the “Event of Default” condition in the contract between Toshiba and ENGIE.

Under Toshiba’s policy to eliminate risks related to the overseas nuclear power construction business, Toshiba has invited new investors to participate in NuGen, and also considered the sale of Toshiba Group’s shareholding in NuGen. However, notwithstanding negotiations with multiple companies, Toshiba is unable to anticipate to complete the sale of NuGen during FY2018, to March 31, 2019. After considering the additional costs entailed in continuing to operate NuGen, Toshiba recognizes that the economically rational decision is to withdraw from the UK nuclear power plant construction project, and has resolved to take steps to wind-up NuGen.

Excellent thread, anyone who is a non-UK native will, having read this thread, now recognise that the UK government, virtually irrespective of the political leaning it may have, cannot organise anything for toffee.

Here you have a major national infrastructure project, early on the drawing board, being dogged by nonsense and in all likelihood doomed to failure from the very first steps: here we are discussing about the additional cost and complexity involved in burying the transmission lines because a mere 14 miles of it passes into a national park. The UK is a joke in this respect. We have becomes so sensitive to the needs and wants of 'stakeholders' that any project will be wrapped around its own axle in moments.

No no, forget the plant, lets cover the country in wind turbines instead.

Speaking in parliament during a debate on the nuclear industry that was secured by Copeland MP Trudy Harrison, Mr Woodcock said thousands of jobs would be lost and Britain’s energy security compromised unless the government snaps out of its near-paralysis over Brexit. Mr Woodcock told MPs that in the past Cumbria has proved itself a world leader in nuclear energy and it can do so again if the government agrees to take control of building the stalled nuclear power plant. He said he was sick of weak governments going cap-in-hand to foreign investors and getting knocked back, putting thousands of local jobs at risk. Addressing energy minister Richard Harrington, who has threatened to resign unless prime minister Theresa May rules out a catastrophic no-deal Brexit in a crunch vote next week, Mr Woodcock said: “The minister and his boss are probably doing God’s work in trying to wrench the government from total madness on the Brexit deal, but that illustrates the lack of focus across government on our wider energy future at a critical time.

'If the newer designs are uneconomical, older AGR should be continued with.'
The fact that Britain failed to export any AGRs would suggest that nobody outside the country found them competitive. If the Brits had built PWRs instead - as the French did at the same time, after abandoning their own graphite/gas design - there wouldn't be such urgency to replace their nuclear fleet now. PWRs could easily be life-extended for another thirty years; the AGRs have cracking graphite, and it's not possible to replace it. The graphite in molten salt reactors like Flibe's or Terrestrial's should be a lot easier - the reactor is much more compact, and doesn't have a pressure vessel to get in the way. (The Russian RBMK is also built to allow repair and replacement of the graphite.)

'If the newer designs are uneconomical, older AGR should be continued with.'
The fact that Britain failed to export any AGRs would suggest that nobody outside the country found them competitive. If the Brits had built PWRs instead - as the French did at the same time, after abandoning their own graphite/gas design - there wouldn't be such urgency to replace their nuclear fleet now. PWRs could easily be life-extended for another thirty years; the AGRs have cracking graphite, and it's not possible to replace it.

Despite the litany of messes created in the AGR programme, it has not been a total failure.
However it is worth noting that PWR was never going to be built in the 2nd Generation build programme, during the reactor competition it was eliminated in the first round.

It essentially came down to the AGR, the SGHWR (which is a pressure tube boiling light water heavy water moderated reactor) and a BWR.

I would have preferred the SGHWR or BWR myself, but the PWR was never really in the running.

The graphite in molten salt reactors like Flibe's or Terrestrial's should be a lot easier - the reactor is much more compact, and doesn't have a pressure vessel to get in the way. (The Russian RBMK is also built to allow repair and replacement of the graphite.)

Well a modern AGR would use a prestressed cast iron vessel that could be dismantled to gain entry to the internals, but that was only really concieved off in Germany in the mid seventies.
I did a design exercise for my masters which I called EAGR ('Eager')

Given that the modern PWRs appear essentially unbuildable.
Our choices boil down to trying to rush the ESBWR through or build CANDUs because they are a simple design that has a reputation for being delivered on time and on budget.

It wasn't very sophisticated, it was just a short outline study on the potential of doing three things to the AGR:

1) Using a prestressed cast iron pressure vessel that could be reopened as required, and weighed a tiny fraction of the concrete vessel, made the plant something like 15m shorter due to its thinner walls and a thus shorter fuel string, and would be factory fabricated for site assembly.

3) Replace the coolant blowers with a two stage system such that a separate set of blowers circulated the gas in the reentrant flow, this allows the removal of the baffle plate, a resultant reduction in coolant circuit pressure drop - which gives us improved efficiency and improved cooling in an emergency.

I estimated I could reach 50%+ efficiency and significantly reduce costs, but it would require a development programme that could run to years.